1.
State what is meant by gas exchange in the lungs.
[1 mark]
- oxygen in, carbon dioxide out
JD SCIENCE
Digestion and circulation
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by an alveolus.
[1 mark]
- air sac adapted for gas exchange
3.
State what is meant by the circulatory system.
[1 mark]
- transports blood around the body
4.
State what is meant by haemoglobin.
[1 mark]
- red pigment in red blood cells that binds oxygen
5.
State what is meant by plasma.
[1 mark]
- liquid part of blood
6.
State what is meant by digestion of protein.
[1 mark]
- protease enzymes break proteins into amino acids
7.
State what is meant by the villus.
[1 mark]
- finger-like projection in the small intestine
8.
State what is meant by breathing.
[1 mark]
- ventilation that moves air in and out of the lungs
9.
State what is meant by coronary heart disease.
[1 mark]
- layers of fatty material in coronary arteries
10.
State what is meant by health.
[1 mark]
- a state of physical and mental wellbeing
11.
Owain is asked about gas exchange in the lungs in a WJEC Biology paper.
(a) [2 marks]
- occurs in alveoli
(b) [3 marks]
- why alveoli have a large surface area
12.
Owain is asked about an alveolus in a WJEC Biology paper.
(a) [2 marks]
- thin wall, moist, good blood supply
(b) [3 marks]
- why a good blood supply maintains the gradient
13.
Owain is asked about the circulatory system in a WJEC Biology paper.
(a) [2 marks]
- heart, vessels, blood
(b) [3 marks]
- why mammals have a double circulation
14.
Owain is asked about haemoglobin in a WJEC Biology paper.
(a) [2 marks]
- forms oxyhaemoglobin
(b) [3 marks]
- why red blood cells have no nucleus
15.
Owain is asked about plasma in a WJEC Biology paper.
(a) [2 marks]
- transports CO₂, urea, hormones, glucose
(b) [3 marks]
- why urea is transported to the kidney
16.
Owain is asked about digestion of protein in a WJEC Biology paper.
(a) [2 marks]
- starts in the stomach (pepsin)
(b) [3 marks]
- why the stomach is acidic
17.
Tidal volume 0.5 dm³, rate 12 /min. Calculate pulmonary ventilation.
[3 marks]
- TV × rate
- Final answer: 6 dm³/min
18.
A red blood cell is 8 µm wide and a capillary is 9 µm. Explain the significance, then calculate the difference.
[3 marks]
- cells flattened against the wall / short path
- Final answer: 1 µm
19.
Heart rate 75 bpm, stroke volume 80 cm³. Cardiac output?
[3 marks]
- Final answer: 6000 cm³/min
20.
A person runs and tidal volume rises from 0.5 to 1.5 dm³ and rate from 12 to 20. Find the new ventilation.
[3 marks]
- Final answer: 30 dm³/min
21.
Cholesterol falls from 6.0 to 4.8 mmol/dm³. Percentage decrease?
[3 marks]
- Final answer: 20%
22.
An athlete's resting HR is 50 bpm. How many beats in 24 h?
[3 marks]
- 50×60×24
- Final answer: 72000
23.
Owain carries out investigating the effect of exercise on heart rate. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: exercise intensity / time
- Dependent: pulse rate
(b) [2 marks]
- same recovery time measurement
- so the test is fair / only one variable is changed
(c) [2 marks]
- finding the pulse inconsistently
24.
Owain carries out using a peak-flow meter or spirometer (demonstration). This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: before/after exercise
- Dependent: peak flow / volume
(b) [2 marks]
- same technique
- so the test is fair / only one variable is changed
(c) [2 marks]
- not a tight seal
25.
Owain carries out food tests linked to digestion products. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: food type
- Dependent: colour
(b) [2 marks]
- same reagent volume
- so the test is fair / only one variable is changed
(c) [2 marks]
- false positive if apparatus is dirty
26.
Owain carries out observing a blood smear or photomicrograph of blood. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: n/a
- Dependent: identification of cell types
(b) [2 marks]
- same magnification
- so the test is fair / only one variable is changed
(c) [2 marks]
- confusing platelets with debris
27.
Compare plasma with red blood cells.
[4 marks]
- plasma transports dissolved substances
- red blood cells transport oxygen
28.
Compare inhalation with exhalation.
[4 marks]
- inhalation: volume up, pressure down
- exhalation: volume down, pressure up
29.
Compare stents with statins.
[4 marks]
- stent is a physical tube in the artery
- statin is a drug that lowers cholesterol
30.
Compare the pulmonary artery with the pulmonary vein.
[4 marks]
- pulmonary artery: deoxygenated to lungs
- pulmonary vein: oxygenated to heart
31.
Apply your knowledge of the villus to this situation: absorb fatty acids / glycerol
[3 marks]
- absorb fatty acids / glycerol
32.
Apply your knowledge of breathing to this situation: pressure falls below atmospheric
[3 marks]
- pressure falls below atmospheric